Hi, A few off cycles could be a response to stress or an ovarian cyst that has now resolved. But without more data, I can t be sure. There are some lab tests that should be done- TSH and prolactin to check for thyroid problems or a small brain growth that can change your cycles (and is easy to fix). If you have recently changed your activity level or gained or lost weight intentionally, this can also affect your cycle. So can working shifts or pulling all-nighters. If you ve moved in with the new group of females this can also change your cycle eventually you will all synchronize. Finally, there are many medications which can affect the cycle. Sometimes cycles can become more irregular and birth control pills can help to regulate the cycle after a few packs. Please see your gynecologist so that you can get things checked out. I hope you understand that the best information I can give you is that it s important to try to find an underlying reason and then to fix the problem. It may not be a serious problem but then your cycles would need to be monitored and no treatment unless it is bothersome to you. Only a closer look will give you the data to make a decision about treatment or observation. Hope I have answered your query. Let me know if I can assist you further. Regards, Dr. Ivan R. Rommstein, General Surgeon